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PURPOSE OF REVIEW: To evaluate the current evidence and literature on treatment options for proximal hamstring injuries. RECENT FINDINGS: Patients with 3-tendon complete tears with greater than 2 cm of retraction have worse outcomes and higher complication rates compared to those with less severe injuries. Endoscopic and open proximal hamstring repair both have favorable patient reported outcomes at 5-year follow up. Proximal hamstring repair in patients who are male, with isolated semimembranosus injury, and have proximal hamstring free tendon rupture are more likely to have earlier return to sports. The Parisian Hamstring Avulsion Score (PHAS) is a validated patient-reported outcome measure to predict return to sports. Proximal hamstring injuries may occur in both elite and recreational athletes and may present with varying degrees of chronicity and severity. Injuries occur most commonly during forceful eccentric contraction of the hamstrings and often present with ischial tuberosity tenderness, ecchymosis, and hamstring weakness. Treatment decision-making is dictated by the tendons involved and chronicity. Many proximal hamstring injuries can be successfully treated with non-surgical measures. However, operative treatment of appropriately indicated proximal hamstring tendon injuries can result in significantly better functional outcomes and faster and more reliable return to sports compared to nonoperative treatment. Both endoscopic and open surgical repair techniques show high satisfaction levels and excellent patient-reported outcomes at short- and mid-term follow-up. Postoperative rehabilitation protocols vary across the literature and ongoing study is needed to clarify the optimal program, though emphasis on eccentric hamstring strengthening may be beneficial.

Objective: With the remarkable advances in diagnostic ultrasound equipment, there is a growing need for ultrasound diagnosis of muscle and soft tissue injuries in sports injuries. Among these, hamstring strains are often difficult to treat and require early and accurate diagnosis. Injuries to the proximal part of the hamstring often take a long time to heal. For this reason, the diagnosis of proximal hamstring injuries is extremely important. The structure of the origin tendon is characteristic, and it is a complex in which the semitendinosus muscle (ST) of the medial hamstring and the long head of the biceps femoris muscle (BFLH) of the lateral hamstring share a conjoint tendon (CT). On the other hand, the semimembranosus muscle (SM) attaches to the ischial tuberosity independently. In this study, we created a classification of injury sites focusing on the origin tendon, and investigated the distribution of injury location, relationship to the player's position, and the detection rate of ultrasound diagnosis. Material and Methods: We used ultrasound and MRI to diagnose 52 university men's rugby players who had suffered a hamstring strain for the first time and investigated the distribution of the injured areas. We performed an ultrasound scan as the initial diagnosis and used MRI as a final diagnostic tool. A classification focusing on the origin of the muscle was created. First of all, it was divided into two types: the BFLH-ST complex type, which originates in the CT, and the SM type, which originates in the SM tendon. We also classified BFLH-ST complex damage, including CT damage, as Type I, a BFLH injury without CT injury as Type II, and a ST injury without CT injury as Type III. We then investigated the distribution of the injury location. The degree of ultrasound detection in each injury type was evaluated in three grades. The frequency of BFLH complex and SM injuries was investigated in players who played the forward (FW) and back (BK) positions. Results: The distribution was 40 limbs (77%) for BFLH-ST complex injury type and 12 limbs (23%) for SM injury type. In the BFLH complex type,19 limbs which met the Type I classification criteria for CT tear, 19 limbs met the Type II, and 2 limbs met the Type III. FWs had a higher incidence of SM injuries and BKs had a higher incidence of BFLH-ST complex injuries. With regard to the detection of muscle injuries via ultrasound, a high rate of detection was possible, except for a slight injury to the myofascial junction of the BFLH. Discussion: In terms of the distribution, the BFLH-ST complex, which shares the same origin tendon (i.e. CT), had a higher frequency of muscle tears than the SM. In addition, CT junction injuries occurred frequently in Type II as well as Type I (=CT injury). One possible cause is that the CT is subject to concentrated traction stress from both the medial and lateral hamstrings. With ultrasound, the detection rate of muscle damage around the BFLH-ST complex and SM originating tendon was high, suggesting that it is useful as an initial diagnosis. From this, it can be said that ultrasound is also useful for primary evaluation of "proximal hamstring injury", which is prone to severe and should be given a final diagnosis using MRI. Conclusions: We created a classification system focusing on the originating tendons and clarified their incidence rates. In this study, ultrasound was found to be useful in the detection of originating tendon injuries. We also identified the characteristic sonographic findings of each type. [ABSTRACT FROM AUTHOR]

Background: The Single Leg Bridge Test (SLBT) is commonly described as a measure of 'hamstring endurance'. Nevertheless, the relationship between the SLBT score and isolated hamstring endurance remains uncertain. Purpose: This study aimed to investigate the correlation between SLBT scores and isolated hamstring endurance in healthy men. Additionally, the study aimed to assess the correlation between the limb symmetry index obtained from the SLBT and hamstring endurance test results. Design: Cross-sectional study. Methods: Forty healthy and physically active men were evaluated at the research laboratory on two separate occasions, with a minimum interval of 48 hours between visits. During each visit, participants performed either the single-leg balance test (SLBT) or the hamstring endurance test on an isokinetic dynamometer, which involved 30 concentric knee flexion repetitions performed at maximum intensity, with an angular velocity of 120°/s and a range of motion of 90°. Correlations were analyzed between SLBT scores and hamstring fatigue indexes provided by peak torque and work outcomes. Results: The SLBT score (27±7 reps) demonstrated no significant correlation with isolated hamstring endurance, as measured by isokinetic peak torque (52±9%; p=0.737, r=-0.038) or work (57±9%; p=0.489, r=0.078). Likewise, the limb symmetry index obtained from the SLBT (99±12%) did not significantly correlate with index from the hamstring endurance test: peak torque (107±26%; p=0.540, r=-0.100) and work (102±18%; p=0.849, r=0.031). Conclusion: The SLBT does not appear to be a suitable tool for measuring isolated hamstring endurance in healthy men. Level of evidence: 3. [ABSTRACT FROM AUTHOR]

The difficulties of rehabilitation after anterior cruciate ligament (ACL) injuries, subsequent return-to-sport (RTS) let alone achieving pre-injury performance, are well known. Isokinetic testing is often used to assess strength capacities during that process. The aim of the present machine learning (ML) approach was to examine which isokinetic data differentiates athletes post ACL reconstruction (ACLR) and healthy controls. Two Random Forest models were trained from data of unilateral concentric and eccentric knee flexor and extensor tests (30°/s, 150°/s) of 366 male (63 post ACLR) as well as 183 female (72 post ACLR) athletes. Via a cross-validation predictive performance was evaluated and the Random Forest showed outstanding results for male (AUC = 0.90, sensitivity = 0.76, specificity = 0.88) and female (AUC = 0.92, sensitivity = 0.85, specificity = 0.89) athletes. The Accumulated Local Effects plot was used to determine the impact of single features on the predictive likelihood. For both male and female athletes, the ten most impactful features either referred to the disadvantageous (injured, non-dominant in control group) leg or to lateral differences. The eccentric hamstring work at 150°/s was identified as the most impactful single parameter. We see potential for improving the RTS process by incorporating and combining measures, which focus on hamstring strength, leg symmetry and contractional work. [ABSTRACT FROM AUTHOR]

Background: Handheld dynamometers provide an accurate measurement of muscle strength and have been shown to have good interrater reliability. The proximal stabilization and fulcrum are two methods of manual muscle testing; however, there is uncertainty about which method may be better for obtaining muscle strength measures. Objective: The purposes were to determine if there was a difference in hamstring strength and to determine the interrater reliability of DPT students using a handheld dynamometer when comparing the proximal stabilization and the fulcrum methods. Methods: A descriptive‐comparative research study that examined two methods of manual muscle testing with the use of a Microfet 2 MMT‐Wireless digital handheld dynamometer. In prone, each participant was instructed to bend their knee to 90° of knee flexion, where the handheld dynamometer was placed on the lower leg for 5 s. Each technique was performed three times, and an average of the series was calculated. Results: Twenty‐nine participants volunteered for this study. The mean scores for Raters 1 and 2 between hamstring testing using the proximal stabilization and fulcrum methods were, respectively, t(28) = −2.041, p = 0.051, and t(28) = −1.990, p = 0.056. The interrater reliability showed good reliability between Rater 1 and Rater 2 for hamstring testing for the proximal stabilization method and fulcrum methods, respectively, ICC = 0.742 (95% CI: 0.452, 0.879), p ≤ 0.001, and ICC = 0.752 (95% CI: 0.472, 0.884), p ≤ 0.001. Conclusion: There are no statistically significant differences between the uses of these two methods in healthy adults; however, there is good interrater reliability of DPT students. [ABSTRACT FROM AUTHOR]

Definition: Hamstring injuries (HSIs) are prevalent in sports that involve changes in direction, kicking, and sprinting. These injuries are a major cause of time lost from competition, practice, and training, as well as increased healthcare costs. In a Division I collegiate football program, the authors implemented a multifactorial approach that included repeated performance assessments, detailed data analysis, and a flexible strength and conditioning regimen. Over a three-year period, this resulted in no game time loss due to HSI. This model can be adapted and implemented across sports settings. [ABSTRACT FROM AUTHOR]

Purpose: Proximal hamstring tears may present with neurological dysfunction due to compression or stretching of the sciatic nerve. The purpose of this study was to evaluate the effectiveness of hamstring repair with concurrent sciatic nerve neurolysis for clinical outcomes and patient symptoms. Methods: A retrospective chart review of patients who were diagnosed with hamstring injury at a large tertiary care institution was conducted. Patients with chronic tears (> 6 weeks from injury to surgery) who underwent hamstring repair were reviewed for demographics, clinical variables including symptoms of sciatic neuritis, sciatic nerve abnormalities on MRI, and postoperative outcomes. Chi-square tests were used for categorical variables, t test for continuous variables. Pairwise t tests were used to compare average pre- and postoperative strength for patients with and without symptoms of sciatic neuritis. Results: Thirty-two patients with chronic hamstring tears were included in the analysis. Patients were 59.4% female with an average age of 51.4 years (SD 13.1). Preoperatively, 27 patients (84.4%) were noted to have symptoms of sciatic neuritis. These patients did not differ in age (p =.677) or sex (p =.374) from patients without preoperative symptoms. Sciatic nerve abnormalities were noted on MRI report in 7 patients who had sciatic nerve symptoms and 0 patients who did not have sciatic nerve symptoms. Symptomatic improvement was seen in 21/26 (81%) of patients who had preoperative neurological symptoms, and in 6/7 (86%) of patients with MRI findings. All patients had equivalent or improved strength postoperatively. Conclusion: A sciatic nerve neurolysis is a safe and effective procedure to perform on patients with preoperative sciatic nerve symptoms and chronic hamstring tears that leads to improvement in neurological symptoms and strength. In neurologically asymptomatic patients with chronic hamstring injuries and MRI findings indicating possible nerve damage, a discussion should be held about the risks and benefits of performing a sciatic nerve neurolysis. [ABSTRACT FROM AUTHOR]

Background: The effects of pelvic tilt control using visual biofeedback on gluteus maximus (GM), multifidus (MF), and hamstring (HAM) muscle activities during bridge exercises involving anterior pelvic tilt (APT), neutral pelvic tilt (NPT), and posterior pelvic tilt (PPT) were investigated. Methods: Twenty-five healthy participants were included (mean age, 24.6 ± 1.9 years). Visual biofeedback was used for the participants to self-control pelvic tilt during the bridge exercises. Pelvic tilt controls were performed in a random order (APT vs. NPT vs. PPT) following 30 minutes education program. GM, MF, and HAM muscle activities were measured by surface electromyography. One-way repeated analysis of variance and Bonferroni post hoc test were used. Result: GM and MF muscle activities significantly differed among the different pelvic tilting controls (APT vs. NPT vs. PPT) (p <.017). GM muscle activity during the exercise involving PPT was significantly higher than that involving APT and NPT (p <.017). In contrast, MF muscle activity during the exercise involving PPT was significantly lower than that involving APT (p <.017). In addition, the GM/Right MF, GM/Left MF, and GM/HAM muscle activity ratios during the exercise involving PPT were significantly greater than those involving APT and NPT (p <.017). Conclusions: The bridge exercise involving PPT using visual biofeedback can be recommended as a home exercise to selectively improve the muscle activity of the GM and the muscle activity ratio of the GM/HAM and GM/MF. This information may be valuable for clinicians seeking exercise programs to target specific muscles effectively. [ABSTRACT FROM AUTHOR]

Sustained hamstring pain induces enhanced proprioceptive processing and deficits in peripersonal spatial processing. These findings may hold significance for hamstring reinjury risk and rehabilitation strategies. Recurrent hamstring injuries are highly prevalent amongst sporting populations. It has been hypothesised that pain from an initial hamstring injury may induce reorganisation of somatosensory representations that could contribute to reinjury. However, because of the cross-sectional nature of existing research, it remains unknown whether somatosensory changes are a cause or effect of pain or if they are driven by other potentially confounding factors. Here, we explored the effect of experimentally induced sustained hamstring pain on tasks that interrogate somatosensory and spatial representations. Fifty healthy participants were randomly allocated to an experimental group that performed an eccentric exercise protocol on the right hamstring to induce delayed onset muscle soreness or a control group performing a repetition-matched concentric exercise protocol. The tactile cortical representation was assessed using two-point discrimination and tactile localisation, whereas the proprioceptive representation was assessed using a left–right judgement task. Peripersonal spatial representations were assessed using an auditory localisation task. Assessments were performed at baseline and day 2. No between-group differences in tactile acuity were observed. However, improvements in left–right judgments and worsening of auditory localisation occurred in the experimental group compared with the control group. This study provides preliminary evidence showing that somatosensory changes occur in response to sustained hamstring pain. Experimentally induced, sustained hamstring pain elicited enhancements in proprioceptive processing and deficits in peripersonal spatial processing, suggesting a shift in the allocation of attentional resources from the external (peripersonal) to internal (body) environment. These findings may hold important implications for reinjury risk and rehabilitation following hamstring pain. [ABSTRACT FROM AUTHOR]

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Background: Anterior cruciate ligament reconstruction (ACLR) involves surgically restoring the injured ACL through the placement of graft material. The selection of graft material plays a crucial role in ensuring optimal knee stability postsurgery. Using autografts of the hamstring, bone-patellar tendon-bone (BPTP), quadriceps, and peroneus longus tendon (PLT), the current systematic study aimed to assess the clinical and functional results of patients undergoing ACLR. Methods: Literature search exploration was conducted using databases such as PubMed, Medline, Web of Science, and Cochrane Library, supplemented by additional resources such as Google Scholar and clinical trials.gov, spanning from 2014 to 2024. The two-part tool was employed to analyze five distinct domains. For evaluation of the quality of diagnostic accuracy studies, a quality assessment tool was implemented. Results: Seventeen studies were incorporated. Most studies indicated considerable enhancements in clinical function, postsurgical knee stability, and osteoarthritis alterations. Nonetheless, these autografts present a reduced risk of certain complications including anterior knee pain, discomfort during kneeling, and extension loss. The assessment of risks in the study revealed that 50% were categorized as having a low risk, whereas 32% had an unclear risk and 18% of cases were classified as not applicable. Conclusion: The present systematic review highlights the survival rates and joint stability across various graft options including BPTP, hamstring, quadricep, and especially PLT. These autografts are safe, reliable, and versatile choices deserving of attention in forthcoming ACL reconstruction investigations.

Abstract Background The Functional Assessment Scale for Acute Hamstring Injuries (FASH) which measure symptom’s severity and impact on physical activity and sports ability in individuals with acute hamstring muscle injury, is not available in Persian. The aim of this study was to translate and cross-culturally adapt the FASH questionnaire to Persian and to assess the psychometric properties of the translated version. Methods The Persian-translation and cross-cultural adaptation processes were based on World Health Organization method. A total of 160 participants compromising of four groups: (1) acute hamstring injury (N = 40), (2) other lower extremity injury (N = 40), (3) risk of acute injury (N = 40), and (4) healthy control (N = 40) were recruited to complete the Persian version of FASH (FASH-P) questionnaire twice with an interval of 48–60 h. The Short Form Health Survey (SF-36) and Lower Extremity Functional Scale (LEFS) were used to assess the criterion validity. Test-retest reliability, internal consistency, criterion validity, Dimensionality and floor/ceiling effects were evaluated to assess the FASH-P psychometric properties. Results The FASH questionnaire were translated to Persian without any major problems. The FASH-P showed excellent power of differentiation because the scores were significantly different among the four groups. Regarding psychometric performances, excellent test–retest reliability (Intraclass correlation coefficient of 0.997) and a high level of internal consistency (Cronbach’s alpha of 0.966) were observed. The FASH-P total score was significantly correlated with SF-36 and LEFS questionnaires representing an excellent criterion validity. No floor or ceiling effect were found for total score in Hamstring muscle injury group. Conclusions Due to the excellent psychometric performance, the FASH-P can be used as a reliable and valid tool for evaluating the severity of symptoms and sports ability in Persian-speaking patients with hamstring muscle injury.

The Nordic hamstring exercise (NHE) is effective at decreasing hamstring strain injury risk. Limited information is available on the in vivo mechanics of the bicep femoris long head (BFLH) during the NHE. Therefore, the purpose of this study was to observe kinematic, neuromuscular and in-vivo mechanics of the BFLH during the NHE. Thirteen participants (24.7 ± 3.7 years, 79.56 ± 7.89 kg, 177.40 ± 12.54 cm) performed three repetitions of the NHE at three horizontal planes (0°, 20° and −20°). Dynamic ultrasound of the dominant limb BFLH, surface electromyography (sEMG) of the contralateral hamstrings and sagittal plane motion data were simultaneously collected. Repeated measures analysis of variance with Bonferroni post hoc corrections were used on the in vivo mechanics and the kinematic and sEMG changes in performance of the NHE. Likely differences in ultrasound waveforms for the BFLH were determined. Significant and meaningful differences in kinematics and in vivo mechanics between NHE variations were observed. Non-significant differences were observed in sEMG measures between variations. Changes to the NHE performance angle manipulates the lever arm, increasing or decreasing the amount of force required by the hamstrings at any given muscle length, potentially changing the adaptive response when training at different planes and providing logical progressions ore regressions of the NHE. All NHE variations result in a similar magnitude of fascicle lengthening, which may indicate similar positive adaptations from the utilization of any variation.

Background/Objectives: The optimal graft, particularly in combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries, remains controversial. We evaluated the influence of graft choice between bone-patellar tendon-bone (BPTB) and hamstring autografts on clinical outcomes in combined ACL and MCL injuries. Methods: This retrospective analysis included patients with concurrent ACL and MCL injuries who underwent single-bundle ACL reconstruction with BPTB (group B) or hamstring (group H) grafts, between 2010 and 2019, with a ≥2-year follow-up. Patients were classified based on the MCL injury grade (I, II, or III). Clinical outcomes were assessed through knee stability evaluations using valgus stress radiographs and the KT-2000 arthrometer, patient-reported outcomes using the International Knee Documentation Committee (IKDC) subjective score and Lysholm score, and radiologic outcomes using the IKDC radiographic grade. Results: The study included 169 patients (group B, 92; group H, 77). No significant between-group differences in knee stability or functional outcomes were found after follow-up. Within the same MCL injury grade, particularly in high-grade MCL injuries, BPTB grafts resulted in significantly better medial stability (side-to-side difference in medial joint opening on valgus stress radiographs: grade II, p = 0.006; grade III, p = 0.039) and functional outcomes (IKDC subjective score: grade II, p = 0.045; grade III, p = 0.038) than hamstring grafts. In the hamstring group, higher-grade MCL injuries were associated with worse outcomes (Lysholm knee score, p = 0.009; IKDC subjective score, p = 0.015). Conclusions: Graft choice in ACL reconstruction with concomitant MCL injuries may affect clinical outcomes, particularly in high-grade MCL injuries. Although both graft types performed similarly overall, BPTB grafts provided superior medial stability and functional results in higher-grade MCL injuries. However, caution is needed when interpreting these results due to limitations such as the small sample size and the lack of randomization in graft selection. [ABSTRACT FROM AUTHOR]

Purpose: Eccentric quasi-isometric (EQI) resistance training is emerging as a promising option in sports medicine and rehabilitation. Despite prior research on EQI contractions in quadriceps and biceps brachii, their use in hamstring injury contexts is underexplored. Therefore, our study examines and contrasts the biomechanics and fatigue effects of EQI training on knee extensors and flexors. Methods: Following familiarization, 16 healthy, active participants (9 men, 7 women; 23.5 ± 2.6 years, 72.1 ± 12.8 kg, 173.4 ± 10.7 cm) performed, in random order, four EQI contractions for knee extensions and flexions, respectively. EQI contractions were isotonically loaded to 70% of concentric (60°·s−1) maximal voluntary contraction. Rest between repetitions was set at three minutes, while four minutes separated each muscle group. Peak torque, mean torque, and optimal angle were evaluated pre- and post-bouts. Inter-repetition contraction time and angular velocity were also assessed. Results: Average torque was 160.9 ± 44.2 and 71.5 ± 23.2 Nm for the extensors and flexors. Peak and mean torque significantly decreased for both extensors (p < 0.001, d = 0.70–0.71) and flexors (p ≤ 0.022, d = 0.36) after EQI contractions, respectively. However, the optimal angle increased for extensors (p < 0.001, d = 1.00) but not flexors (p = 0.811, d = 0.06). During EQI contractions, knee flexors exhibited greater intra-repetition velocity than extensors (p = 0.002; η2 = 0.50). Decreases in inter-repetition time and range of motion were more consistent for the extensors. Conclusions: Distinct responses exist when comparing EQI contractions of the knee extensors and flexors, particularly their effect on peak torque angles. These findings suggest knee flexors may require lower relative intensities to align more closely with extensor EQI contractions. [ABSTRACT FROM AUTHOR]

Purpose: Most athletes experience short-term training cessation because of illness, injury, post-season vacation, or other reasons. Passive muscle stiffness is a potential risk factor for a sprint-type hamstring strain injury, but limited information is available about the effect of short-term training cessation on passive muscle stiffness. The present study aimed to identify whether and how passive muscle stiffness of the biceps femoris long head (BFlh) would vary due to 2 weeks of training cessation in sprinters. Methods: Passive BFlh shear-wave speed (a proxy for stiffness) was measured using ultrasound shear-wave elastography in 28 male sprinters, before and after 2 weeks of intervention. During the 2 weeks, the participants in the training-cessation group (n = 14) were allowed to maintain their normal daily activities but not to perform any physical training, including stretching and resistance exercises. The participants in the training continuation group (n = 14) performed the training (including maximum speed sprint, plyometric, and weight training) prescribed by their coaches 5 days per week. Results: In the training-cessation group, passive BFlh shear-wave speed increased after the 2 weeks of training cessation (4.75 ± 0.77 to 5.00 ± 0.88 m/s, P < 0.001). In contrast, there was no significant difference before and after the 2 weeks of training continuation (4.90 ± 0.85 to 4.93 ± 0.85 m/s, P = 0.521). Conclusions: The present findings indicate that muscles stiffen by training cessation in sprinting athletes. [ABSTRACT FROM AUTHOR]

Background: Football is a leading cause of sports-related injuries, accounting for more than half of time-loss injuries in men's collegiate sports. Amniotic membrane and umbilical cord (AM/UC) powder injection is a novel treatment that may aid in functional recovery and return to play in collegiate athletes due to its anti-inflammatory, anti-scarring, and pro-regenerative properties. Methods: A single-center, retrospective chart review was performed on consecutive college football players who sustained acute muscle or ligament tear and were subsequently treated with 50 or 100 mg injection of AM/UC powder (Clarix Flo, BioTissue, Miami, FL). Data collection included patient demographics, diagnosis, grade and extent of injury, position of the player, time to return to play (in days), and complications. Results: Ten athletes with tears of the medial collateral ligament (n=3), hamstring (n=6), and abdomen (n=1) were included for analysis. The majority (n=6) of tears were partial (grade 2), with partial to full tears (grade 2± 3) noted in 2 patients, and a complete tear (grade 3) noted in 2 patients. Athletes returned to play 29.6 ± 15.2 days post-injury, with 80% of athletes returning to play within 4 weeks. No complications or re-injuries occurred during the follow-up period of 6 months. Conclusion: Injection of AM/UC powder is a safe treatment that enables quick return to play in this cohort of football players suffering from muscle or tendon tears. Prospective, randomized studies are warranted to verify whether injection of AM/UC can hasten return to play compared to the current standard treatment. Level of Evidence: IV. [ABSTRACT FROM AUTHOR]

Acute effects of static stretching (SS) and proprioceptive neuromuscular facilitation (PNF) on local and non-local range of motion (ROM) were assessed in 29 participants. Three evaluations were performed one week apart: week-1 Control session (CS); weeks 2–3 either SS or PNF interventions (randomized). Dominant and non-dominant limbs, local (hamstring extensibility) and non-local ROMs (Shoulder extension-ShE) were collected at baseline (T0), immediately after (T1), and fifteen minutes post-intervention (T2). No differences were found between time-points during the CS. Local-ROM significantly increased (p=0.0002, ES=0.74 and 0.0079, 0.56, for dominant and non-dominant lower limbs, respectively) after both SS and PNF. No interaction between time and treatment was detected for ShE in both limbs. However, post-hoc analysis revealed a significant increase in dominant upper limb ShE between T0 and T1 only after SS (p=0.002; +6.5%). Acute bouts of SS and PNF can increase local-ROM, however, no clear effects were observed for non-local ROM. [ABSTRACT FROM AUTHOR]

Background: Hamstring (HS) strength deficits and imbalances have been identified as risk factors for sustaining anterior cruciate ligament (ACL) injuries and muscular strains, with HS injuries being the most prevalent muscle injuries in soccer athletes. The aim of this study was to investigate HS eccentric strength before and after a soccer match in both male and female soccer athletes. Hypothesis: Soccer athletes have changes in eccentric HS strength after a soccer game. Study Design: Cohort observational study. Level of Evidence: Level 3. Methods: HS eccentric strength (mean and absolute peak torque and total work) was measured in 64 healthy male and female competitive football athletes (14-25 years) with an automatic device during the execution of the Nordic hamstring exercise (NHE) test before and after a 90-minute soccer match. The anterior-knee laxity (AKL) was quantified with an arthrometer. Results: Mean and absolute eccentric HS peak torque decreased by 24.5 N.m (-12.34%; P < 0.01) and 21.9 N.m (-10.08%; P < 0.01) in female athletes, whereas their male peers improved by 19.9 N.m (+9.01%; P = 0.01) and by 20.9 N.m (+8.51%; P = 0.02), respectively. HS total work in female athletes decreased by 831.1 J (P < 0.01) compared with the male athlete reduction of 235.3 J. Both the pre- versus postmatch intersex mean and absolute eccentric HS peak torque changes were significant (P < 0.01), as were the changes in HS total work (P < 0.01). The pre- versus postmatch AKL difference and the dominant versus nondominant limb comparison of the strength parameters were not significantly different. Younger female athletes (14-19 years old) presented a greater decrease in mean and absolute peak HS eccentric strength compared with those in older female athletes and men. Conclusion: HS eccentric strength and work differ based on athlete sex, as measured by the NHE test. Mean peak, absolute peak, and total work showed greater reductions in female athletes than those in their male peers. The subgroup of 14- to 19-year-old female athletes experienced the highest reduction in strength parameters. [ABSTRACT FROM AUTHOR]

Background. Isokinetic dynamometer is a widely used and valid method to evaluate bilateral torque symmetries and agonist-antagonist muscular ratios that may be implicated in injury risk. Therefore, this study aimed to evaluate the inter-limb strength asymmetries and the conventional hamstring:quadriceps ratio (H:Q) of dominant and non-dominant limbs at two angular velocities (60 and 300°/s) in athletes of basketball (BA), American football (AF), futsal (FT) and running (RU). Methods. Fifty-seven athletes participated in the study. All athletes underwent body composition assessments and, subsequently, were tested in an isokinetic dynamometer. After warming up, all athletes performed two maximal voluntary isometric contraction of knee extension-flexion during five seconds each. The subjects also performed five repetitions of concentric knee extension-flexion in two angular velocities (60 and 300°/s). All analysis used a significance level of α = 0.05. Results. There was no imbalance (higher than 15%) between limbs in any of the evaluated athletes. None of the evaluated groups showed imbalances in conventional H:Q ratio during high angular speed. AF, FT and RU demonstrated conventional H:Q asymmetries in low angular velocity. The BA group was the only one that showed a balanced conventional H:Q ratio in both limbs and in both angular velocities evaluated. Conclusions. None of the evaluated groups had inter-limb strength limb asymmetry. The BA group was the only one fully balanced in both angular velocities while AF, FT and RU were imbalanced only for concentric H:Q ratio in low angular velocity. [ABSTRACT FROM AUTHOR]

Despite increased awareness of the multifactorial nature of Hamstring Strain Injury (HSI), the role of running biomechanics remains unclear. The aim of this systematic review was to investigate whether an association exists between running biomechanics and HSI. Five databases were searched from inception to January 2021. Eligibility criteria included epidemiological studies that provide data on running biomechanics in athletes who have sustained a HSI (retrospectively or prospectively) and compared to control data. Searches yielded 4,798 articles. Twelve met the selection criteria. Biomechanical analysis differed considerably across studies, thus meta-analyses was not possible. Studies largely found either no differences or contradicting findings between running biomechanics of athletes who have sustained a HSI (retrospectively or prospectively) and controls, with the exception of lateral trunk kinematics and horizontal propulsive forces. It is important to note some concern regarding the quality of included studies, particularly sample size, increasing the risk of bias associated with results. Further research utilising validated methods of biomechanical analysis, is needed to determine if an association exists between running biomechanics and HSI. Until then, definitive conclusions cannot be drawn as to whether specific biomechanical interventions should be included in injury prevention and/or rehabilitation programmes. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the mid‐term clinical outcomes for the non‐surgical and surgical management of acute proximal hamstring avulsions. Methods: Sixty physically active individuals were offered surgical or non‐surgical management for their proximal hamstring avulsion injuries. Distal retraction was defined as greater than 2 cm. Primary outcome measures were the Victorian Institute of sport assessment‐proximal hamstring tendons (VISA‐H) and functional assessment scale for acute hamstring injuries (FASH). Secondary outcome measures included palpable gap (cm), return to sport (RTS) and the ability to perform Nordic hamstring curls. Outcome variables were adjusted in regression models for gender, age, and treatment. Results: Thirty‐one patients elected to undertake non‐surgical management, and 29 chose surgery with a mean follow‐up of 34.8 ± 8.7 and 34.9 ± 7.0 months, respectively. The mean VISA‐H for the non‐surgical and surgical groups were 87.3 ± 3.4 and 87.9 ± 4.1 (n.s.), respectively. The mean FASH for the non‐surgical group was 89.3 ± 2.4 and 88 ± 3.6 for the surgical group (n.s.). This was consistent after adjusting for confounders. The mean gap for the non‐surgical group was 4.5 ± 1.09 and 4.9 ± 1.19 cm for the surgical group (n.s.). No significant differences were found in the abilities to perform Nordic hamstring curls (n.s.). Both groups achieved comparable RTS rates (n.s.). On average, the non‐surgical group achieved RTS at 5.5 ± 1.2 months post‐injury, whereas the surgical group was at 5.7 ± 0.7 months (n.s.). Conclusion: Physically active individuals with acute proximal hamstring avulsions and distal retraction of the tendon stump can be managed non‐surgically, achieving similar functional levels and RTS compared to patients treated surgically. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Objective: This study was planned to determine the reliability, validity, and applicability of the isolated hamstring flexibility test (IHFT). Design: A cohort study (diagnosis); level of evidence, 2. Setting: It was performed in the research and application laboratory. Participants: Seventy-five individuals aged 18 to 25 years, selected through simple probability random sampling, with a normal Beighton Horan and Joint Mobility Index scores, and who volunteered to participate, were included for evaluation. Interventions: On then first and third days, participants underwent muscle strength, sit-and-reach test, active knee extension test, IHFT for validity and reliability. Stretching exercises were prescribed as a home program for 31 patients with limited knee extension, and measurements were repeated at the end of the eighth week. Main outcomemeasures: Sit-and-reach test, active knee extension test, IHFT. Results: The test-retest reliability was high (intraclass correlation coefficient, 0.993). Our test demonstrated validity when compared in terms of flexibility gained. A significant difference was found between pre-post stretching exercise training in all 3 tests (P, 0.05). Conclusion: It was observed that the IHFT is reliable and applicable in determining hamstring flexibility. Given the absence of another test specifically measuring hamstring flexibility in isolation, its indirect validity was established through analysis with other tests using the gold standard for assessing gains in hamstring flexibility. [ABSTRACT FROM AUTHOR]

The adductor magnus ischiocondylar origin (AM‐IO) tendon has often been described as a third proximal hamstring tendon due to its common origin on the ischial tuberosity as well as similar function. Prior studies have described the magnetic resonance imaging characteristics of the AM‐IO; however, its appearance on ultrasound has not been well‐detailed. The purpose of our study is to describe the sonographic appearance of the AM‐IO and provide a structured scanning protocol for complete evaluation of the tendon. Access the CME test here and search by article title. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Physical Education & Sports Studies is the property of Journal of Physical Education & Sports Studies and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hamstring injuries remain a significant concern in the world of professional sports, and the Australian Football League (AFL) is no exception. With its unique combination of high-speed running, sudden directional changes, and physical contact, AFL places considerable demands on athletes' lower extremities, making them susceptible to hamstring injuries. These injuries not only affect player performance but also pose a substantial economic burden on clubs due to treatment costs and missed game time. Hamstring strains remain the most common injury resulting in missed matches in the AFL with an incidence of 4.94 new injuries per club compared to 4.86 in 2020 (1), and the most common cause of matches missed with 20 AFL matches missed per club. The reasons why hamstring injuries are occurring more despite all the research and performance tracking is unknown, but a theory is that players are pushing their performance to the boundary despite dedicated prevention strategies. The purpose of this article is to show how to structure the rehabilitation for different hamstring injuries based on classifications from the BAMIC. This impacts when players are given certain exercises and stages of rehab running based on healing timeframes and athlete's function (5). The methods used to write this article, included reviewing the most up-to-date literature on hamstring injuries and rehabilitation (2, 3, 8, 12) then using this knowledge to program the rehabilitation for hamstring injuries sustained during the 2023 season for the Manly Wolves, who are part of the premier division of AFL Sydney. The main findings and key practical recommendations are established in the rehabilitation timeline for each case study and will give S&C coaches and physiotherapists guidelines for how to best return their AFL players to play. [ABSTRACT FROM AUTHOR]

The management of proximal hamstring tear (PHT) is debated and consensus regarding recommended measures and individual treatment regimens is lacking. The present investigation evaluated the efficacy of a conservative management of partial and complete PHT. The present observational study was conducted following the STROBE statement. In June 2018 the medical databases of the BG Klinikum Bergmannstrost Halle, Germany were accessed. All the patients with PHT were retrieved. The outcomes of interest were to evaluate the clinical examination, PROMs, imaging, and isokinetic muscle strength at the baseline and last follow-up. 31 patients were enrolled in the present study. Nine patients (29 % (9 of 31) described local pain at the ischial tuberosity in sitting situations and also in manual palpation. A persistent gap in the tendon string beneath the tuberosity in manual palpation was reported in 25.8 % (8 of 31). The mean VAS at the last follow-up was 2.3 ± 2.3. The mean LEFS score was 50.9 ± 18.8. Control MRI at follow-up showed scarring restitution in the proximal tendon in all patients in the partial tear group. In the complete tear group, a persisting defect state of the proximal tendon course was found in 45 % (9 of 20). The injured side achieved 81.5 ± 22.2 % of the force of the uninjured side, measured in the flexion movement at 60°/s. At an angular velocity of 240°/s, 83.2 ± 26.3 % of the force of the uninjured side was achieved. According to the main findings of the present study, conservative therapy of PTH tears is associated with good clinical outcomes. High-quality investigations are required to establish the proper therapeutic algorithm and advantages of conservative management compared to a surgical approach. Level III. • The management of proximal hamstring tear is debated and consensus regarding recommended measures and individual treatment regimens is lacking. • Conservative therapy of proximal hamstring tear tears is associated with good clinical outcomes. • High-quality investigations are required to establish the proper therapeutic algorithm and advantages of conservative management. [ABSTRACT FROM AUTHOR]

The Nordic hamstring exercise (NHE) is effective at decreasing hamstring strain injury risk. Limited information is available on the in vivo mechanics of the bicep femoris long head (BFLH) during the NHE. Therefore, the purpose of this study was to observe kinematic, neuromuscular and in-vivo mechanics of the BFLH during the NHE. Thirteen participants (24.7 ± 3.7 years, 79.56 ± 7.89 kg, 177.40 ± 12.54 cm) performed three repetitions of the NHE at three horizontal planes (0°, 20° and −20°). Dynamic ultrasound of the dominant limb BFLH, surface electromyography (sEMG) of the contralateral hamstrings and sagittal plane motion data were simultaneously collected. Repeated measures analysis of variance with Bonferroni post hoc corrections were used on the in vivo mechanics and the kinematic and sEMG changes in performance of the NHE. Likely differences in ultrasound waveforms for the BFLH were determined. Significant and meaningful differences in kinematics and in vivo mechanics between NHE variations were observed. Non-significant differences were observed in sEMG measures between variations. Changes to the NHE performance angle manipulates the lever arm, increasing or decreasing the amount of force required by the hamstrings at any given muscle length, potentially changing the adaptive response when training at different planes and providing logical progressions ore regressions of the NHE. All NHE variations result in a similar magnitude of fascicle lengthening, which may indicate similar positive adaptations from the utilization of any variation. [ABSTRACT FROM AUTHOR]

Introduction: Athletes with CP were more prone to limb injuries. Stretching had long been considered beneficial for improving muscle performance and reducing the risk of injury. Proprioceptive Neuromuscular Facilitation was a technique used to enhance muscle elasticity and increase peak torque and muscle strength. Objective: To analyze the effect of adding Proprioceptive Neuromuscular Facilitation exercises on quadriceps and hamstring muscle strength in cerebral palsy athletes. Methodology: The study was conducted at the NPC Indonesia Training Center. The subjects consisted of 24 athletes diagnosed with cerebral palsy, aged 18-40 years, who underwent intervention three times per week for four weeks on both limbs. The subjects were divided into two groups: 12 individuals in the treatment group received a resistance training program with additional Proprioceptive Neuromuscular Facilitation exercises, and 12 in the control group underwent resistance training only. Results: There was a significant increase in muscle strength in the treatment group for the dominant quadriceps (p=0.043), non-dominant quadriceps (p=0.001), dominant hamstring (p=0.002), and non-dominant hamstring (p=0.008). In the control group, significant increases were observed in the dominant hamstring (p=0.024) and non-dominant hamstring (p=0.013), but not in the dominant quadriceps (p=0.530) or non-dominant quadriceps (p=0.420). Compared to the control group, a significant difference was found in non-dominant quadriceps strength (p=0.020), but no differences were observed in dominant quadriceps strength (p=0.396) or hamstring strength (p=0.271, p=0.204). Conclusions: The addition of Proprioceptive Neuromuscular Facilitation exercises significantly increased quadriceps and hamstring strength in cerebral palsy athletes compared to those without it.

Anomalous muscles are rarely seen in the popliteal region of the lower limb. Some of them are harmless and go unnoticed and some create problems such as neuropathies. We report a novel case of an unusual additional muscle in this region. The additional muscle was closely associated with the short head of the biceps femoris muscle. It took its origin from the lower part of the lateral supracondylar line and the adjoining popliteal surface of the femur. The muscle was 10 cm in length, 1 cm in breadth and was fleshy throughout. It was oriented parallel to the medial side of the tendon of biceps femoris. It was inserted to the posterior aspect of the head of the fibula, medial to the insertion of the biceps femoris. The additional muscle derived its nerve supply from the sciatic nerve. The common peroneal nerve was closely related to the medial border of the additional muscle. [ABSTRACT FROM AUTHOR]

Background: Injuries of the proximal attachment of the hamstring muscles are common. The present study aimed to investigate the relationship of the proximal attachment of the hamstring muscles with neighboring structures comprehensively. Methods: A total of 97 hemipelvis from 66 cryopreserved specimens were evaluated via ultrasound, anatomical and histological samples. Results: The proximal attachment of the hamstring muscles presents a hyperechogenic line surrounding the origin of the semimembranosus and the long head of the biceps femoris muscles, as well as another hyperechogenic line covering the sciatic nerve. The anatomical and histological study confirms the ultrasound results and shows different layers forming the sacrotuberous ligament. Furthermore, it shows that the proximal attachment of the semimembranosus muscle has a more proximal origin than the rest of the hamstring muscles. Moreover, this muscle shares fibers with the long head of the biceps femoris muscle and expands to the adductor magnus muscle. The histological analysis also shows the dense connective tissue of the retinaculum covering the long head of the biceps femoris and semimembranosus muscles, as well as the expansion covering the sciatic nerve. Conclusions: These anatomical relationships could explain injuries at the origin of the hamstring muscles. [ABSTRACT FROM AUTHOR]

Purpose: This study highlights the pattern of presentation, treatment, early functional outcome, and complications observed in the management of chronic patellar tendon ruptures using our preferred technique of autogenous semitendinosus graft reconstruction. Methods: This was a retrospective case series involving consecutive patients who underwent patellar tendon reconstruction and met the inclusion criteria. The outcome measures were determined by the post-operative knee range of motion (R.O.M), the post-operative International Knee Documentation Committee (IKDC) score, and pattern of post-operative complications. Results: Nine patients were included in this case series. The mean age of the patients was 35.4 ± 6.8 years (range 27–44 years). Trauma to the knee accounted for majority of the cases (62.5%). Six (66.7%) of the nine patients suffered a patellar tendon rupture from contact injury during sporting activities. The mean length of time from injury to presentation was 20.5 ± 11.2 weeks (range 6–69.5 weeks). Normal knee function in a case (11.1%), nearly normal knee function in 7 cases (77.8%), and abnormal knee function in a case (11.1%) were recorded as a measure of outcome of surgery. The mean post-operative IKDC score was 70.0 ± 6.1 (range 55–77), which was higher than the mean pre-operative score of 26.4 ± 5.1 (range 18–32). The post-operative knee R.O.M averaged 97.2 ± 16.2° (range 70–120°) with a single case with a 10° extension lag noted. Conclusion: Normal to near-normal knee function was obtained with the treatment of chronic patellar tendon rupture in the majority of cases using autogenous semitendinosus graft for patellar tendon reconstruction in our series. [ABSTRACT FROM AUTHOR]

Assessing muscle activation during squat and countermovement jumps is crucial for soccer players because these exercises replicate the explosive movements often required in competition, such as jumping for a header. Objective: The objective of this study is to examine the activation patterns of the rectus abdominis, lumbar erector spinae, rectus femoris, and biceps femoris on both the left and right sides in male and female soccer players during squat jumps (SJs) and countermovement jumps (CMJ). Methodology: This cross-sectional study included 30 healthy university-level players (15 males and 15 females). Surface electromyography (Noraxon-USA, MR3 3.8.30) was used to assess the activation patterns of the rectus abdominis, lumbar erector spinae, rectus femoris, and biceps femoris on both sides during SJs and CMJs. Results: The Pearson correlation coefficient was used to determine the relationship between left and right muscle activation patterns in male and female players during both types of jumps, revealing a significant correlation (p < 0.05). Discussion: Females exhibited more consistent left-right synchronization in muscle activation, especially in the core and leg muscles, compared to males, who showed more complex muscle interactions and asymmetries. These findings align with previous research indicating that men and women differ in their neuromuscular activation patterns, co-contraction ratios, and responses to dynamic movements such as jumping. Understanding these gender-specific patterns is important for developing targeted training and injury prevention strategies. Conclusion: The findings indicated that different jump types and genders displayed distinct muscle activation patterns. Females, in particular, demonstrated a significantly stronger correlation between the left and right muscle activation during both jumps compared to males. [ABSTRACT FROM AUTHOR]

Objective: To investigate the associations of thigh muscle and fat volumes with structural abnormalities on MRI related to knee osteoarthritis. Materials and Methods: MRI studies of the thighs and knees from 100 individuals were randomly selected from the Osteoarthritis Initiative Cohort. Whole Organ MR Scoring (WORMS) and effusion-synovitis scoring were performed in all knee MRI. Thigh muscles, intermuscular fat, and subcutaneous fat were manually segmented in 15 consecutive MR thigh images. Radiographic Kellgren-Lawrence grades (KLG) were also obtained in all knee radiographs. Independent t-tests were used to investigate the associations between thigh muscle and fat volumes, and sex. Mixed-effects analyses were obtained to investigate the associations between thigh muscle and fat volumes, KLG, WOMAC pain score, cartilage and bone marrow WORMS, as well as effusion-synovitis scores. Results: Women had higher subcutaneous fat volume than men (616.82 vs. 229.13 cm3, p < 0.01) and men had higher muscle volumes than women (p < 0.01). Quadriceps (coef = -2.15, p = 0.01) and vastus medialis (coef = -1.84, p = 0.03) volumes were negatively associated with the WORMS cartilage scores. Intermuscular fat volume (coef = 0.48, p = 0.01) was positively associated with WORMS bone marrow edema-like lesion (BMEL) scores. The quadriceps (coef = -0.99, p < 0.01) and hamstring (coef = -0.59, p = 0.01) volumes were negatively associated with WORMS BMEL scores. No evidence of an association was found between thigh muscle and fat volumes with KLG and effusion-synovitis grading (p > 0.05). Conclusion: Increased quadriceps and hamstring volumes were negatively associated with cartilage lesion and BMEL scores while no evidence of an association was found between thigh muscle and fat volumes, and radiographic knee osteoarthritis or effusion-synovitis grading. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the utility of semitendinosus tendon (ST) and gracilis tendon (GT) cross‐sectional area (CSA) on magnetic resonance imaging (MRI) and anthropometric characteristics in preoperative estimation of graft diameter in patients undergoing anterior cruciate ligament reconstruction (ACLR) with four‐strand hamstring autografts. Methods: Three databases were searched on 29 August 2023. The authors adhered to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta‐Analyses) and R‐AMSTAR (Revised Assessment of Multiple Systematic Review) guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, anthropometric characteristics, imaging techniques, tendon CSA, correlation coefficients, sensitivities, specificities, regression models and cutoffs for predicting intraoperative graft diameters above 8 mm were recorded. Results: Forty‐six studies comprising 4140 patients were included. Twelve of 19 (63.2%) studies reporting on ST + GT CSA found a moderate to very high correlation with intraoperative graft diameter. Five of 10 (50%) and one of seven (14.3%) studies reporting on ST CSA and GT CSA, respectively, found a moderate to high correlation with intraoperative graft diameter. Cutoffs of ST + GT CSA for predicting graft diameters above 8 mm ranged from 15.8 to 31.2 mm2. Nine of 35 (25.7%) studies that reported on height found a moderate to very high correlation with graft diameter. Seven of 33 (21.2%) studies reporting on weight found a moderate correlation with graft diameter. Conclusion: Of the MRI parameters assessed, ST + GT CSA was the most reliable predictor of graft diameter. However, cutoffs, sensitivities, and specificities for predicting diameters above 8 mm were highly variable. Anthropometric characteristics in general were less predictive of graft diameter than MRI parameters. This information can be used by clinicians to predict patients at risk for ACLR failure due to insufficient graft size. Level of Evidence: Level IV. [ABSTRACT FROM AUTHOR]

Measuring the bicep femoris long head fascicle length via the use of diagnostic ultrasound has become common practice within elite sport, using single images of between 4 and 6 cm. No study to date has compared single image estimations in terms of the varying fields of view (i.e., 4, 6, and 10 cm). Therefore, the aim of this study was to determine whether differences occur when estimating the bicep femoris long head fascicle length using short (4 cm), medium (6 cm), and long (10 cm) fields of view across three estimation equations. A total of 36 male athletes (age: 23.8 ± 3.8 years, body mass: 83.7 ± 14.0 kg, height: 1.81 ± 0.06 m) had three ultrasound images of the bicep femoris long head collected on a single occasion with the fascicle length estimated. A significant main effect was observed (p < 0.001) with moderate–very large differences (p < 0.078, d = 0.91–4.01). The smallest fields of view resulted in the greatest fascicle length. There were significant moderate–large associations between the fields of view (p < 0.001, r = 0.542–0.892). Unacceptable limits of agreement were observed, and the developed correction equations remained unacceptable. The partial measure equation is the most accurate whilst using the 10 cm fields of view, while the basic trigonometry equation had the lowest variability between fields of view and the smallest differences between fields of view; hence, this equation may be more appropriate when a <6 cm field of view is the only field of view available. [ABSTRACT FROM AUTHOR]

Background: In ACL reconstruction, it is desirable to assess preoperatively whether a sufficient graft diameter can be achieved with the planned tendon graft. The present study investigated the effect of the location of the cross-sectional area (CSA) measurement of the hamstring tendons in preoperative MRI on the correlation of the CSA with the intraoperative graft diameter. In addition, we analyzed whether the measurement results of examiners with different skill levels were comparable. Methods: A total of 32 subjects undergoing a single bundle ACL reconstruction using an autologous ipsilateral quadrupled hamstring graft (STGT) were included. The CSA of the semitendinosus and gracilis tendon was determined in preoperative MRI on six defined levels by three examiners. The intraclass correlation coefficient between the measurements of these observers was determined. The correlation between the sum of the CSA of both tendons (CSA STGT) and the graft diameter was investigated. Results: The interrater reliability was excellent on most of the investigated levels. A significant correlation between CSA STGT and the graft diameter was seen on all levels. The strongest correlation was found on the level 10 mm above the joint line. Conclusions: The measurement of the CSA STGT in the preoperative MRI 10 mm above the joint line enabled a good assessment of the achievable graft diameter in ACL reconstruction, independent of the examiners' training level. [ABSTRACT FROM AUTHOR]

Objective: The hamstring muscles in soccer are the region with the highest percentage of muscle injuries, due to numerous risk factors, including isometric strength levels. In this way, the aim is to know and establish a strength profile in this musculature in elite Asian players. Method: During the first part of the preseason, an elite soccer team (N=46 players) belonging to the AFC Champions League underwent isometric hamstring strength assessment at 30º and 90º, using a dynamometry device ( ForceFrame ®, Valdperformace). Results: Among the results obtained, an average profile in Isometric Force (N) at 30º of 268 N (+- 46.4), an average profile of Isometric Force (N) at 90º of 206 N (+- 42.1) is observed. ), a bilateral asymmetry (%) at 30º of 2.23% (+- 12.2) and a bilateral asymmetry (%) at 90º of 6.46% (+- 15.9). Regarding the correlation between measured variables, a moderate positive correlation (0.732, p=0,001) is observed between the average of bilateral Isometric Strength (N) at 30º and at 90º. Conclusions: In light of the results obtained, it is observed that the players in the present sample present higher levels of isometric strength at 30º than at 90º, nevertheless presenting higher % of bilateral asymmetry at 90º compared to 30º. Keywords: Neuromuscular, Hamstring, injuries, Strength, Isometric

Abstract Posterior tibial translation (PTT) after double-bundle posterior cruciate ligament (PCL) reconstruction has sometimes occurred. Purpose of this study is to identify the risk factors for postoperative PTT after double-bundle PCL reconstruction with a hamstring autograft. Comparing the results of bilateral gravity sag view (GSV) at 12 months after surgery, over 5-mm PTT was defined as ‘failure’ in this study. Of 26 isolated PCL reconstruction cases, over 5-mm PTT was seen in 7 cases (group F: 9.57 ± 1.28 mm), and 19 cases had less than 5 mm (group G: 2.84 ± 1.29 mm). Age, sex, body mass index (BMI), preoperative GSV, posterior slope angle of the tibia, anterolateral bundle (ALB) and posteromedial bundle (PMB) graft diameters, and tibial tunnel diameter were evaluated. The two groups were compared with the 2 × 2 chi-squared test, the Mann Whitney U-test, and Spearman’s rank correlation coefficient. Multivariate logistic regression analysis was also performed to determine the risk factor. Statistical significance was indicated as p

Introduction: The diameter of the quadrupled Hamstring graft plays a significant role in the incidence of graft failures for ACL reconstruction. The ability to predict the graft size pre-operatively can prepare the surgeon for alternatives in the event of an inadequate graft diameter. Materials and methods: We retrospectively measured the diameter of the Semitendinosus tendon (ST) on the MRI in all patients who underwent arthroscopic ACL reconstruction using quadrupled Semitendinosus as their graft. We also estimated any correlation between various anthropometric data with pre-operative MRI based Cross Sectional Area (CSA) of the Hamstring tendon and final graft diameter in the South Asian population. The patients were included from Jan 2018 - Dec 2020. Results: The minimum CSA of ST to predict an eventual graft diameter of 7.5mm was 10.7mm2. The MRI based cross-sectional area measurement showed moderate correlation with the intra-operative graft diameter obtained. (r=0.62, p

The molecular and cellular basis of health in human tendons remains poorly understood. Among human tendons, hamstring tendon has markedly low pathology and can provide a prototypic healthy tendon reference. The aim of this study was to determine the transcriptomes and location of all cell types in healthy hamstring tendon. Using single nucleus RNA sequencing, we profiled the transcriptomes of 10 533 nuclei from four healthy donors and identified 12 distinct cell types. We confirmed the presence of two fibroblast cell types, endothelial cells, mural cells, and immune cells, and identified cell types previously unreported in tendons, including different skeletal muscle cell types, satellite cells, adipocytes, and undefined nervous system cells. The location of these cell types within tendon was defined using spatial transcriptomics and imaging, and potential transcriptional networks and cell–cell interactions were analyzed. We demonstrate that fibroblasts have the highest number of potential cell–cell interactions in our dataset, are present throughout the tendon, and play an important role in the production and organization of extracellular matrix, thus confirming their role as key regulators of hamstring tendon homeostasis. Overall, our findings underscore the complexity of the cellular networks that underpin healthy human tendon function and the central role of fibroblasts as key regulators of hamstring tendon tissue homeostasis. [ABSTRACT FROM AUTHOR]

The ischial origin of the hamstring musculature is complex. While the conjoint tendon and semimembranosus are commonly discussed and understood by radiologists, there is a lesser-known origin of the semitendinosus along the inferior and medial surface of the ischium in the form of a broad direct muscular connection. This secondary origin is infrequently described in the radiology literature and is a potential pitfall during grading of semitendinosus injuries if the interpreting physician is unaware of its presence. In a proximal hamstring tendon tear, the direct muscular origin of the semitendinosus can be spared, torn along with the conjoint tendon, or remain intact and contribute to a vertical shearing injury of the semitendinosus myotendinous junction. Detailed knowledge of this anatomy and its imaging appearance in the setting of injury enables the reader to correctly diagnose these unique hamstring injuries. [ABSTRACT FROM AUTHOR]

BACKGROUND: Conventional hamstring (HAM) stretching therapeutic effects are not substantiable in neuromusculoskeletal conditions with HAM tightness or shortness. We developed a kinetic chain stabilization exercise to provide a more sustainable effectiveness in adults with HAM tightness. However, its therapeutic effects and underlying motor mechanisms remain unknown. OBJECTIVE: To compare the effects of traditional active HAM stretching (AHS) and kinetic chain stretching (KCS) on electromyographic (EMG) amplitude and hip flexion range of motion (ROM) in participants with HAM tightness. METHODS: In this randomized controlled trial, 18 participants (mean age: 25.01 ± 2.47 years) with HAM tightness were assigned to the AHS or KCS group. Hip joint movement, EMG amplitude, and onset times were recorded in the bilateral erector spinae, HAM, transverse abdominis/internal oblique (IO), external oblique (EO), and rectus abdominis during a straight leg raise test. RESULTS: Compared to AHS, KCS led to greater increase in the hip flexion ROM and EMG activation amplitudes in the left and right EO and left IO. Post-test hip flexion ROM data in both the groups were higher than the pre-test data. CONCLUSION: KCS produced more sustainable effectiveness in hip flexion movement and EMG motor control patterns in participants with HAM tightness than AHS. [ABSTRACT FROM AUTHOR]

Background: Qualitative movement screening tools provide a practical method of assessing mechanical patterns associated with potential injury development. Biomechanics play a role in hamstring strain injury and are recommended as a consideration within injury screening and rehabilitation programs. However, no methods are available for the in-field assessment of sprint running mechanics associated with hamstring strain injuries. Purpose: To investigate the intra- and interrater reliability of a novel screening tool assessing in-field sprint running mechanics titled the Sprint Mechanics Assessment Score (S-MAS) and present normative S-MAS data to facilitate the interpretation of performance standards for future assessment uses. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Maximal sprint running trials (35 m) were recorded from 136 elite soccer players using a slow-motion camera. All videos were scored using the S-MAS by a single assessor. Videos from 36 players (18 men and 18 women) were rated by 2 independent assessors blinded to each other's results to establish interrater reliability. One assessor scored all videos in a randomized order 1 week later to establish intrarater reliability. Intraclass correlation coefficients (ICCs) based on single measures using a 2-way mixed-effects model, with absolute agreement with 95% CI and kappa coefficients with percentage agreements, were used to assess the reliability of the overall score and individual score items, respectively. T -scores were calculated from the means and standard deviations of the male and female groups to present normative data values. The Mann-Whitney U test and the Wilcoxon signed-rank test were used to assess between-sex differences and between-limb differences, respectively. Results: The S-MAS showed good intrarater (ICC, 0.828 [95% CI, 0.688-0.908]) and interrater (ICC, 0.799 [95% CI, 0.642-0.892]) reliability, with a standard error of measurement of 1 point. Kappa coefficients for individual score items demonstrated moderate to substantial intra- and interrater agreement for most parameters, with percentage agreements ranging from 75% to 88.8% for intrarater and 66.6% to 88.8% for interrater reliability. No significant sex differences were observed for overall scores, with mean values of 4.2 and 3.8 for men and women, respectively (P =.27). Conclusion: The S-MAS is a new tool developed for assessing sprint running mechanics associated with lower limb injuries in male and female soccer players. The reliable and easy-to-use nature of the S-MAS means that this method can be integrated into practice, potentially aiding future injury screening and research looking to identify athletes who may demonstrate mechanical patterns potentially associated with hamstring strain injuries. [ABSTRACT FROM AUTHOR]

Background and Purpose Hamstring strength testing is crucial in assessing this important muscle group during rehabilitation and injury prevention. The purpose of this study was to evaluate the reliability and validity of measuring strength in a maximally lengthened position using a handheld dynamometer (HHD) compared to isokinetic testing. Methods Twenty healthy and active participants were recruited, and isometric strength testing was performed both on the Biodex machine and isometric end-range hamstring testing with the HHD on two occasions. Results Significant strong correlations (r= 0.87, p < 0.0001) were found between strength testing on the Biodex machine and the HHD for both the right and left sides. Bland-Altman plots demonstrated agreement between the two measurements. Excellent intra-rater reliability (ICC= 0.91-0.93) and moderate to good inter-rater reliability (ICC = 0.71-0.83) for the HHD test was demonstrated. Conclusions The HHD provides a reliable and valid alternative to isokinetic testing for assessing hamstring strength in a maximally lengthened position. This assessment can be valuable in monitoring rehabilitation progress and detecting deficits before and after returning to play. The HHD is an accessible and cost-effective option for assessing hamstring strength at long lengths in a clinical setting. Level of evidence 3 [ABSTRACT FROM AUTHOR]

Copyright of Turkish Journal of Sport & Exercise / Türk Spor ve Egzersiz Dergisi is the property of Turkish Journal of Sport & Exercise and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)